An official informed on Monday that the Principal Advisor to Lucknow Metro Rail Corporation (LMRC) E. Sreedharan has submitted his resignation. He has decided to quit citing health issues. The LMRC has forwarded the letter of Padma Vibhushan receiver to the state govt. for approval. Sreedharan is also known by the name 'Metro Man' because of his experience in handling mega Metro projects in the country.